1. Field of the Invention
The present invention relates to a TFT (thin film transistor) array panel using aluminum wiring.
2. Description of the Related Art
A larger screen liquid crystal display (LCD) (e.g., wide-screened high definition LCD) requires longer and narrower wiring. High resistance wiring materials may cause RC delay and degrading a picture quality. Wiring materials having relatively high melting points (e.g., tantalum, chrome, titanium, or an alloy thereof) are no longer suitable for a large screen LCD because of their high resistance values. Wiring materials having relatively low resistances are silver, copper, aluminum, etc. Silver and copper are not suitable wiring materials because of poor adhesion with amorphous silicon.
Due to the drawbacks of other wiring materials, aluminum is a more suitable wiring material for a large screen LCD. However, aluminum is susceptible to a hillock problem. FIG. 1 shows a hillock 2100 protruding from an aluminum line 2000 and damaging an insulating layer 3000 (e.g., SiNx). The hillock 2100 includes a thin and long whisker 2110. An active layer 4000 (e.g., amorphous silicon) formed on the insulating layer 3000 is also damaged. The hillock 2100 may cause short-circuit between the aluminum line 2000 and the active layer 4000 or between the neighboring aluminum wiring lines 2000. Also, the hillock 2100 may cause a TFT to be defective. Thus, there is a need for improving wiring for a larger LCD.